Despite reports of her potential involvement last week, Jessica Chastain will not be appearing in Iron Man 3, the actress herself revealed via her Facebook page.

“Sorry to say that ‘Iron Man’ 3 isn’t going to work out,” she writes. “My schedule is jammed packed and I can’t fit anything else in. The press announced my possible attachment far too soon. I know many of you wanted me to be involved, and I’m so sorry to disappoint you. Hopefully there’ll be another Marvel film in my future. Shane Black and everyone on the IM3 team are really wonderful. I’m very excited to see the film when it comes out. xx”

Chastain was said to be up for the role of a scientist that is the intellectual equal of Robert Downey Jr.’s Tony Stark. Although it’s not confirmed, it’s possible that the role is that of Dr. Maya Hansen, a character responsible for the “Extremis” nanotechnology that is said to be a key part of the sequel’s focus.

Written and directed by Shane Black (and co-written by Drew Pearce), Iron Man 3also stars Robert Downey Jr., Gwyneth Paltrow, Don Cheadle, Ben Kingsley and Guy Pearce and is set for release on May 3, 2013.